1. Field of the Invention
The present invention relates to a terminal device, and more specifically, it relates to a terminal device performing prescribed processing on multimedia data transmitted by a remotely set data broadcasting station.
2. Description of the Background Art
Conventionally, a terminal device receiving and displaying multimedia data has been developed. The terminal device gets the multimedia data in the following manner: Multimedia data is previously stored in a WWW (World Wide Web) server. The terminal device accesses this WWW server through the Internet on the basis of a user""s instruction, for retrieving necessary multimedia data. Conventionally, a method of getting multimedia data has been mainly the so-called pull type, such a method that the user pulls out the data.
Against the pull type, recently a demand for a method of pushing out data toward the user (the so-called push type), i.e., multimedia data broadcasting is increasing. For example, DAB (Digital Audio Broadcasting) of EUREKA-147 project in Europe exactly corresponds to this push type. In this multimedia data distribution, the user indicates to the terminal device the channel transmitting necessary data. The terminal device automatically receives and displays the data through the channel. Thus, the user of the terminal device can readily get multimedia data with operation feeling similar to that for the conventional television or radio. This multimedia data distribution has such an advantage that processing of retrieving necessary data may not be performed.
In this multimedia data distribution, the broadcasting station cannot receive a request from the user""s terminal device in real-time. Consequently, it is difficult to control the contents of broadcast multimedia data on the user side. For example, even if the user desires to get already distributed multimedia data, he cannot transmit the request therefor to the broadcasting station, and hence it is difficult to get the multimedia data. As a method of solving such a problem and providing the user with a degree of flexibility for reference to the multimedia data, it is conceivable to set in the terminal device a storage device (typically a hard disk drive) for storing and managing multimedia data. Thus, when continuously storing multimedia data distributed from the broadcasting station in the storage device, the terminal device can get, for example, already broadcasted multimedia data from this storage device. Thus, the degree of flexibility for the user in reference to the multimedia data is improved.
Multimedia data has a large size. In order to continuously store the multimedia data, the terminal device must comprise a storage device having a sufficiently large capacity. However, it is difficult for the terminal device to comprise a mass storage device due to restriction of its space and cost. Therefore, the terminal device must effectively utilize a storage device having a limited capacity. As one method of such effective utilization, there is such a method that the storage device stores and deletes received multimedia data in a time-series manner so that the terminal device can regularly get newest multimedia data, for example. In this method, however, there has been such a problem that multimedia data frequently referred to by the user is also deleted in a time-series manner.
Therefore, an object of the present invention is to provide a terminal device which can effectively utilize the capacity of a storage device without deleting multimedia data frequently referred to by the user.
The present invention has the following aspects to achieve the object above.
A first aspect of the present invention is directed to a terminal device performing prescribed processing on multimedia data distributed by a data broadcasting station distributing multimedia data identical with each other at time intervals in a broadcasting form, comprising:
a receiving part receiving the multimedia data distributed by the data broadcasting station, a management part creating and managing management information as to the multimedia data received by the receiving part,
a storage device storing the multimedia data for which the management information has been created by the management part, and
a reference part requesting multimedia data to the management part while letting the user refer to the requested multimedia data,
wherein the management part
creates as part of the management information a retention coefficient indicating whether or not to delete each multimedia data in the storage device,
decrements each created retention coefficient at a prescribed timing while incrementing the retention coefficient of the multimedia data requested by the reference part,
deletes, when the created retention coefficient is decremented to a prescribed value, the corresponding multimedia data from the storage device, and
deletes, when new multimedia data identical to old multimedia data in the storage device is inputted, the old multimedia data from the storage while letting the management information for the old multimedia data inherited as management information for the new multimedia data.
As described above, in the first aspect, the management part increments/decrements the retention coefficient on the basis of the frequency of reference by the user to the multimedia data. Namely, if the multimedia data is not at all referred to, its retention coefficient is immediately decremented to the prescribed value. If the multimedia data is frequently referred to, on the other hand, the retention coefficient is incremented. When the retention coefficient reaches the prescribed value, the management part deletes the corresponding multimedia data from the storage device. Therefore, multimedia data having a small frequency of reference is preferentially deleted from the storage device, while multimedia data having a large frequency of reference is contrarily retained in the storage device over a long period. According to the first aspect, as described above, the multimedia data in the storage device can be customized in a state preferable for the user. Further, multimedia data having a small frequency of reference is immediately deleted, whereby the capacity required by the storage device can be suppressed.
In the first aspect, further, multimedia data identical with each other is distributed to the terminal device. The management part lets the management information for the old multimedia data inherited as the management information for the new multimedia data. If this old multimedia data is frequently referred to by the user, its retention coefficient has a large value. Therefore, the new multimedia data, the retention coefficient of which is set from the beginning at a large value, is hard to delete from the storage device. Namely, multimedia data highly interesting to the user and being new are regularly stored in the storage device. Thus, it follows that the multimedia data in the storage device are customized for the user in a further preferable state.
According to a second aspect, in the first aspect, the management part further
creates, when the multimedia data requested by the reference part is not stored in the storage device, temporary-management-information as to the multimedia data in advance, and
lets, at a time point when the multimedia data requested by the reference part is inputted in the management part, the corresponding temporary-management-information inherited as management information for the inputted multimedia data.
The reference part may request multimedia data not yet stored in the storage device to the management part. Such multimedia data requested but not yet stored is in the future transmitted and stored in the storage device. As described above, in the second aspect, the management part creates, even if the requested multimedia data is not yet stored in the storage device, temporary-management-information for the multimedia data. The management part creates, at the time point when such multimedia data is stored in the storage device, management information inheriting the temporary-management-information. Namely, the management part can create a retention coefficient having a large value from the beginning. Therefore, such multimedia data is hard to delete from the storage device. Thus, it follows that the multimedia data in the storage device are customized for the user in a further preferable state.
According to a third aspect, in the second aspect, the management part further
searches multimedia data (hereinafter referred to as related-multimedia-data) being related to the multimedia data requested by the reference part, and
increments the retention coefficient of the found related-multimedia-data.
As described above, in the third aspect, the data broadcasting station transmits to the terminal device multimedia data being related to each other. The management part increments not only the retention coefficient of the multimedia data requested by the reference part but also the retention coefficient of the multimedia data being related thereto. Therefore, it follows that the related-multimedia-data also remains in the storage device for a long time. Thus, it follows that the multimedia data in the storage device are customized for the user in a further preferable state.
According to a fourth aspect, in the third aspect, the management part further searches the related-multimedia-data in a search range specified by the reference part.
As described above, in the fourth aspect, the management part gets the related-multimedia-data belonging to a specific range. Namely, it is possible to reliably select only multimedia data being related to the requested multimedia data. Thus, it follows that the multimedia data in the storage device are customized for the user in a further preferable state.
According to a fifth aspect, in the third aspect, the management part further increments the retention coefficient of the related-multimedia-data on the basis of the degree of the relation to the multimedia data requested by the reference part.
Each found related-multimedia-data does not necessarily have a given degree of relation to the reference part. If uniformly incrementing retention coefficients of related-multimedia-data, therefore, related-multimedia-data less related to the requested multimedia data remains stored in the storage device for a long time. As described above, in the fifth aspect, the retention coefficient of the related-multimedia-data is incremented on the basis of the degree of relation to multimedia data requested by the reference part. With reference to the requested multimedia data, therefore, closely-related multimedia data tends to remain in the storage device for a long time. Thus, it follows that the multimedia data in the storage device are customized for the user in a further preferable state.
According to a sixth aspect, in the third aspect, the management part further
creates, when the found related-multimedia-data is not stored in the storage device, temporary-management-information as to the related-multimedia-data in advance, and
lets, at a time point when related-multimedia-data not yet stored in the storage device is inputted in the management part, the corresponding temporary-management-information inherited as management information for the inputted related-multimedia-data.
The management part may select multimedia data not yet stored in the storage device as related-multimedia-data. Such non-stored/relevant multimedia data is in the future transmitted and stored in the storage device. As described above, in the sixth aspect, the management part creates, even if selected related-multimedia-data is not yet stored in the storage device, temporary-management-information for this multimedia data. The management part creates, in storage of the related-multimedia-data, management information inheriting the temporary management information. Namely, the management part can create a retention coefficient having a large value from the beginning. Therefore, this related-multimedia-data is hard to delete from the storage device. Thus, it follows that the multimedia data in the storage device is customized for the user in a further preferable state.
According to a seventh aspect, in the third aspect, the management part further outputs, when new multimedia data identical to multimedia data or related-multimedia-data thereof being referred by the user with the reference part is inputted in the management part, the inputted new multimedia data to the reference part.
As described above, in the seventh aspect, the management part immediately outputs the aforementioned new identical multimedia data to the reference part when it is inputted. Therefore, the reference part can get, with no requirement to the management part, multimedia data very interesting to the user and being new in real-time from the management part, and let the user refer to the multimedia data. Thus, the terminal device becomes more user-friendly.
According to an eighth aspect, in the seventh aspect, the management part further re-outputs, after a given time passes since the new multimedia data is outputted to the reference part, the multimedia data referred to immediately before the new multimedia data.
As described above, in the eighth aspect, the management part re-outputs, after a given time passes since the new multimedia data is outputted to the reference part, the multimedia data referred to by the user immediately before the new multimedia data. In this way, the multimedia data which has been referred to immediately before the input of the new multimedia data is referred again by the user. The series of processing is automatically performed by the management part, and hence requires no specific operation to the user. Thus, the terminal device becomes more user-friendly.
According to a ninth aspect, in the seventh aspect, the management part further does not output, on the basis of an instruction from the reference part, the multimedia data newly inputted in the management part to the reference part.
The reference part in the seventh aspect lets the user refer to the multimedia data sequentially and continuously outputted from the management part. Namely, the multimedia data to be referred to by the user is switched every time multimedia data is inputted to the reference part. According to the ninth aspect, the management part stops, on the basis of the instruction from the reference part, the output of the newly inputted multimedia data. Thus, the reference part can require the management part to stop outputting the multimedia data as required. Thus, the reference part can let the user refer to specific multimedia data, among multimedia data sequentially and continuously inputted, for a long time. Thus, the terminal device becomes further more user-friendly.
According to a tenth aspect, in the first aspect, multimedia data distributed by the,data broadcasting station is coded in a predetermined coding format,
the terminal device further comprises a decoding part for decoding the multimedia data received by the receiving part in accordance with the predetermined coding format and outputting the multimedia data to the management part,and
the decoding part and the reference part operate independently of each other.
As described above, in the tenth aspect, the decoding part and the reference part operate independently of each other, whereby the reference part, i.e., the user may not specially operate to store multimedia data in the storage device. The decoding part continuously decodes the distributed multimedia data, whereby the multimedia data can be automatically stored in the storage device.
According to an eleventh aspect, in the first aspect, every time storing multimedia data in the storage device, the management part notifies the reference part of the fact.
As described above, in the eleventh aspect, the reference part is notified that multimedia data is stored in the storage device, whereby the user can understand in real-time that the multimedia data is stored in the storage device.
According to a twelfth aspect, in the first aspect, the management part does not delete, while multimedia data stored in the storage device is outputted by the reference part, the multimedia data from the storage device.
As described above, in the twelfth aspect, the multimedia data is not deleted by the management part from the storage device while it is referred to by the user. Thus, the multimedia data referred to by the user with the reference part is not switched at random.
A thirteenth aspect is directed to a terminal device performing prescribed processing on multimedia data distributed by a data broadcasting station distributing multimedia data identical with each other at time intervals in a broadcasting form, comprising:
a receiving part receiving the multimedia data distributed by the data broadcasting station;
a management part creating and managing management information as to the multimedia data received by the receiving part;
a storage device storing the multimedia data for which the management information has been created by the management part; and
a reference part requesting multimedia data to the management part while letting the user refer to the requested multimedia data,
wherein the management part
creates as part of the management information a retention coefficient indicating whether or not to delete each multimedia data in the storage device,
updates, on the basis of the request for multimedia data by the reference part, a retention coefficient corresponding to the multimedia data,
deletes, when the updated retention coefficient satisfies a prescribed condition, the corresponding multimedia data from the storage device, and
creates, when new multimedia data not identical to multimedia data stored in the storage device is inputted, new management information as to the new multimedia data.
In the thirteenth aspect, the management part updates a retention coefficient on the basis of the frequency of reference to the multimedia data by the user. When the updated retention coefficient satisfies a prescribed condition, the management part deletes the corresponding multimedia data from the storage device while regarding the multimedia data as not being referred to by the user. Consequently, the multimedia data having a small frequency of reference is deleted from the storage device with the highest priority, whereas the multimedia data having a large frequency of reference is retained in the storage device over a long period. As described above, according to the thirteenth aspect, the multimedia data in the storage device can be customized in a state preferable for the user. Moreover, multimedia data having a small frequency of reference is immediately deleted, thereby suppressing the capacity of the storage device. Furthermore, in the thirteenth aspect, multimedia data identical with each other is distributed to the terminal device. The management part creates management information for completely new multimedia data which is not stored in the storage device. In other words, the management part does not create management information as to new multimedia data which is identical with old multimedia data stored in the storage device. That is, the new multimedia data can be managed by management information for the old multimedia data. In this way, inheritance of management information can be realized as in the case with first aspect. Thus, in the terminal device in the present invention, multimedia data very interesting to the user (that is, having a large frequency of reference by the user) and being new is stored in the storage device.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.